Carphone Warehouse SIM Only

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Carphone Warehouse's cheapest SIM-only plan is £6.00 a month, and on 16 September 2026 that bought 20GB with unlimited minutes and texts on a 24-month iD Mobile term, or 10GB on a rolling month with no commitment at all. Every figure on this page was taken that day from the retailer's own SIM-only listings and from the networks' published terms.

There were 14 SIM-only plans on the page across three brands — iD Mobile, Vodafone and VOXI — and not one of them asked for money up front. Terms run at one month, 12 months and 24 months, and the shop prints the contract length, the data, the monthly price and any future increase on the tile itself, so the comparison can be made before you click into anything.

Two things here are better than the market usually manages. iD Mobile's SIM-only plans are exempt from the annual price rise that applies to its handset contracts, so the number you sign at is the number you finish at; and iD lets you roll unused data into the next month at no charge, which is rare on a plan costing less than a round of drinks.

Put a price on the commitment, because this shop lets you

Most mobile pages tell you a longer term is cheaper. On this listing you can check it, because the same brand sells the same plan on three different lengths at once, and the answer is not what the industry implies.

Take iD Mobile's unlimited data plan. It costs £15.00 a month on a rolling month, £15.00 on 12 months and £15.00 on 24 months. The monthly price does not move at all. What moves is the sweetener: the 12-month version carries £50.00 cashback and the 24-month version comes with Apple AirPods 4, while the rolling month carries neither. So the shop is not charging you for flexibility — it is paying you to give it up, and it has named its price. A year of being unable to leave is worth £50.00 here. Decide whether that is a fair rate for your own circumstances rather than assuming the long contract is the bargain.

At the cheap end the trade is made in data instead. £6.00 a month buys 10GB on a rolling month, 15GB over 12 months and 20GB over 24 months. Two years of commitment earns you an extra 10GB a month against walking away whenever you like — a real gain, but a modest one, and it is the same £6.00 either way.

Then there is the case that breaks the rule outright. iD's 50GB rolling-month plan is £7.00. Its 60GB 12-month plan is £8.00. The no-commitment option is a pound a month cheaper and only 10GB smaller, which means a customer who signs for a year on that particular pair is paying £12.00 over the term for the privilege of being locked in. Read the tiles side by side before choosing; the ladder is not always pointing the way you expect.

The country gets through 11.8GB a month. These plans sell up to 120GB

Ofcom's Communications Market Report 2026, published 30 June 2026, puts average monthly data use at 11.8GB per mobile data user across 2025 — up 1.1GB, or 11%, on the year before. That single figure is the most useful thing a SIM-only shopper can carry into this page, because it turns a wall of allowances into a decision.

Against 11.8GB, the plans on offer sort themselves out quickly. The £6.00 10GB rolling plan sits just under the national average, so a typical user would go over it. The £6.00 15GB and £7.00 16GB plans sit just above it, which is roughly where an average user actually lives. The £10.00 120GB plan offers about ten times average use, and the £15.00 unlimited plan offers an amount nobody in the statistics is approaching.

None of that makes the big allowances dishonest — heavy users exist, tethering a laptop eats data fast, and a household that has given up fixed broadband will use far more than 11.8GB. But paying £15.00 for unlimited when you use 12GB is an £8.00 a month decision against the 16GB plan at £7.00, which is £96.00 a year. Check your last three bills for actual usage before you buy headroom you will not touch. iD's free data rollover makes that calculation gentler still, because an unusually quiet month is banked rather than lost.

A fortnight in Europe costs nothing, £15 or £21 — and the SIM decides which

This is where the three brands on one page diverge most sharply, and it is worth more to a holidaymaker than any data allowance.

iD Mobile states on its SIM-only listings that you can "use your allowances in 50 destinations worldwide, up to 30GB", with a 30GB ceiling where the plan allowance is 30GB or more, subject to fair usage. A two-week trip to Spain on the £6.00 plan therefore costs £0.00 extra.

Vodafone works the other way round. Its published global roaming terms include only Zone A in every pay monthly plan — the Republic of Ireland, the Isle of Man, Iceland and Norway. Zone B, which is the 47 European destinations most people actually fly to, needs a pass: £16.00 for eight days or £21.00 for 15 days. A fair use policy of 25GB applies, after which data is charged at £3.83 per GB. For broader coverage Vodafone sells Xtra Global Roam plans covering up to 84 destinations.

VOXI, which is Vodafone's own rolling-monthly brand launched in 2017, sits between the two: European roaming is sold by the day from £2.25 for one day, £4.00 for two, £10.00 for eight and £15.00 for 15, with a 20GB fair usage allowance and unlimited minutes and texts while abroad.

So the same fortnight in Spain is free on the cheapest SIM in the shop, £15.00 on VOXI and £21.00 on Vodafone. If you travel in Europe even twice a year, that gap is larger than most of the price differences between the plans themselves, and it is not shown anywhere on the comparison tiles.

The money back arrives as a cheque, and you have to go and get it

Nine of the 14 plans carry cash or a gift card, and the amounts are substantial against the monthly prices: £42.00 on the £10.00 120GB iD plan and again on the £11.00 60GB Vodafone plan, £50.00 on both the £15.00 iD unlimited plan and the £13.00 Vodafone 120GB plan, £25.00, £20.00, £15.00, £12.00 and £10.00 elsewhere, plus a £50.00 Currys gift card on the £12.00 Vodafone 100GB plan and a £25.00 one on an £8.00 iD plan.

The mechanism is the part to read. The retailer's own terms state that cashback is "given via a cheque, using the recorded name and address for purchases made online up to 60 days from purchase date", and that "if the contract is returned the cashback must be returned". On the Vodafone side one plan shortens that window to 28 days. The gift card on the £12.00 plan is dispatched with the purchase and is valid for six months.

Three things follow. A cheque in 2026 means a bank that still accepts one and a customer who still has somewhere to pay it in. A 28 or 60-day claim window means the money is forfeited by anyone who files the paperwork and forgets. And the clawback clause means the headline saving is not secured until the return period has passed. Treat the cashback as money you have to claim rather than a discount you have been given, and compare the plans on their monthly price first.

Only one of these three brands can put your price up

The annual increase is the thing most people get caught by, and on SIM-only it is avoidable — but only if you pick the right tile.

iD Mobile's listings state plainly that "iD SIM only plans are not subject to annual CPI or RPI price increases", and the network's own price-increases page confirms the exclusion in its own words: the increase "doesn't apply if: You are a SIM Only customer. You are a Pay as You Go customer." A £6.00 iD SIM-only plan taken today is a £6.00 plan for as long as you keep it.

Vodafone's SIM-only plans do rise, and the shop prints the future figures on the tile rather than hiding them. The £8.00 50GB plan shows "£9.50 from 1ST Apr 2027". The £12.00 100GB plan shows £13.50 from the same date. The 24-month plans show two steps: the £23.00 unlimited plan goes to £25.50 in April 2027 and £28.00 in April 2028, and the £13.00 120GB plan goes to £15.50 and then £18.00.

Run that to its conclusion and the gap between the two brands widens over time rather than narrowing. Unlimited data is £15.00 flat on iD and £23.00 rising to £28.00 on Vodafone — a plan that starts 53% dearer and ends 87% dearer. Separately, and on both networks, out-of-bundle charges for anything used outside the allowance still rise by the Consumer Price Index plus 3.9%, which is the one inflation-linked figure that survives on these plans.

The shop sells its own network, and it has grown into a real one

iD Mobile is not a third-party brand that happens to be stocked here. It is Currys' own mobile virtual network operator, and Currys owns Carphone Warehouse, so on most of these tiles the retailer is selling you its own airtime.

That is worth knowing and it is not a criticism. Currys' full-year results for the year to 2 May 2026, published 2 July 2026, report 2.6 million iD Mobile subscribers, up 18% year on year and ahead of the company's own 2.5 million target, with a stated aim of reaching at least 2.8 million before the next year end. A network adding subscribers at that rate is not a side project, and the commercial logic explains why iD's SIM-only pricing on this page is consistently the sharpest of the three brands.

The underlying coverage is Three's. Currys announced a multi-year extension of that arrangement on 17 January 2023, when iD Mobile had 1.2 million customers, citing Three's 4G coverage of over 99% of the UK. So an iD SIM gives you a large network's masts at a small network's prices, which is the whole proposition of a virtual operator and the reason the £6.00 tile is credible rather than suspicious.

What the listings leave you to find out for yourself

Three gaps are worth naming, because a reader who knows about them in advance can settle each with one question.

First, the VOXI section of the site describes the brand, its unlimited social media on Snapchat, Instagram, WhatsApp, Facebook, Pinterest and Facebook Messenger, and its roaming day passes, but does not print the plan prices on the same page as the iD and Vodafone tiles. A brand you cannot price is a brand you cannot compare, and it is the only one of the three in that position here.

Second, the Vodafone increase is not applied at a single consistent rate. Most 12-month plans step by £1.50 in April 2027, but the £10.00 30GB plan steps by £2.50 to £12.50 on the same date, and the 24-month plans step by £2.50 twice. The tiles give the correct figures so nobody is misled, but the reason one 12-month plan is treated differently from the others is not published and we could not establish it — ask before signing if the difference matters to you.

Third, the fair usage and open data policies that sit behind "unlimited" on every brand are referenced on the tiles and set out elsewhere. Unlimited is a commercial description, not a technical one, and the 30GB roaming ceiling on iD and the 25GB and 20GB roaming caps on Vodafone and VOXI are the visible edge of it.

Figures were taken from each provider's own published terms on 16 September 2026. Variable rates can change at any time — confirm the current rate with the provider before applying.